while True:
   a = float(input("请输入第一个数:"))
   b = int(input("请输入运算符(+=1,-=2,*=3,/=4,^=5)"))
   c = float(input("请输入第二个数："))
   if b == 1:
       d = a + c
       print("结果是:",d)
   elif b == 2:
       d = a - c
       print("结果是:",d)
   elif b == 3:
       d = a * c
       print("结果是:",d)
   elif b == 4:
       d = a / c
       print("结果是:",d)
   elif b == 5:
       d = a ** c
       print("结果是:",d)